Heating furnace and burner therefor



Nov. 13, 1945.

F. A. CORBIN ETAL HEATING FURNACE AND BURNER THEREFOR Filed March 13, 1945 7 Sheets-Sheet l FIE- 1.

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HEATING FURNACE AND BURNER THEREFOR Filed March 13, 1943 '7 Sheets-Sheet 3 F'|E-:L

Nov. 13, 1945.

F. A. CORBIN ETAL HEATING FURNACE AND BURNER THEREFOR '7 Sheets-Sheet 4 Filed March 15, 1943 WNQQQ INVENTORS. 59504. (GEE/N 000 #489) F/VETZHQM/VEQ Nov. 13, 1945.

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F. A. cbRBIN ETAL 2,389,027

HEATING FURNACE ANDBURNER THEREFOR Filed Ma rch 13, 1943 '1 Sheets-Sheet s m /vs/r 77M #00195 HI'I WWI I Nov. 13, 1945.

F. A. CORBiN ETAL HEATING FURNACE AND BURNER THEREFOR '7 Shets-Sheet '7 Filed March 13, 1945 g /0 g XII Z5 77 0Q XII INVENTORS. F950 4 COBB/N m1 weer E NETZHfi/V/Vffi 7 Jrra /VEK Patented Nov. 13, 1945 HEATING FURNACE AND BURNER THEREFOR Fred A. Corbin, Germ and Harry F. Netzhammer,

Hobart, In

Application March 13, 1943, Serial No. 479,026 13 lllaims. (c1. 263-40) The present invention relates more particularly to a burner for improving the firing eiilciencies of furnaces for heating steel or other materials. In the following specification, there will be described an embodiment of the present invention as installed in bottom-fired soaking-pit furnaces for heating steel ingots, although the burner of the present invention is not thus limited in its application, but it is adapted to, and equally important in, other types of heating iumaces, such as annealing and melting furnaces for steel, glass and the like, as well as for heat-treating furnaces wherein one or more burner are inserted in an inverted position through the roof. Since the burner of the present invention is adapted particularly to the uniform coverage of definite areas, it is usable to advantage in any furnace where uniform coverage of all exposed sides is desired. This condition is easy of accomplishment in the use of the burner 01' the present invention by inserting one or more of the burners in each wall and the roof.

Insofar as pertains to the heating of soakingpit furnaces for steel ingots, where the furnaces are heated by burners positioned in the bottom of each furnace, such practice, prior to the present invention, is open to certain very definite disadvantages which are obviated.

Among these disadvantages which are inherent in the heretofore standard constructions, there may be mentioned the fact that the burner directs the flame upwardly against the brickwork of the cover where it spends a considerable amount of its heat, as well as damaging and reducing the life of the brickwork, while also following the cover to the walls, the flame is deflected downwardly, and first contacts the ingots at their tops.

There results an uneven applicationof heat over the surfaces of the ingot, the heat being maximum at the top where the flame first contacts theingots, tapering oii down the ingot sides where the flame flows, and escapes through the waste ga ports. There is practically no application of heat to the surfaces near the bottoms of the ingots. This results in a condition in which the tops of the ingots reach the critical temperature while the bottoms still are relatively cold. In this connection, it may be noted that the rate of heat application on the surfaces of the ingots is held at the maximum only until some parts of the ingots reach the critical temperature when it is reduced immediately in order to equal or balance the rate of heat conduction from the surface into the mass of the ingots. Otherwise, the

continue to rise and the steel would become damaged by overheating and burning.

This reduced heating rate, which is known as soaking, is maintained until the temperature of the ingots reaches a specified means, with a limited differential. This diflerential is wider than desirable from a rolling standpoint, but it would require a much longer soaking period to secure any appreciable improvement.

With a heated top and a cold bottom, which result as has been described above, the general direction of heat conduction is parallel to the long axis of the ingot, while the area of conduction, being normal to the direction of conduction, is" across the ingot. These factors combine to cause a slow soaking rate. 0n the other hand, an accelerated rate of heating would elevate rapidly the temperature of the relatively small hot area of the ingot and damage the steel by overheating, burning, and aggravating the pipe.

The heating of the ingots is accomplished in two steps, namely:

1. Transfer of heat from the flame to the ingot surface directly by convection and indirectly by radiation; and

2. Transfer of heat from the surface to the interior, which transfer is dependent on the law of conductivity.

With reference to the foregoing neglecting radiation, heat convection is dependent on theiollowing factors:

1-a Area heated Variable. 1-?) Flame conditions Do The law of conductivity involves the following factors:

2-a Area of conduction Variable.

. Z-b Conductivity factor of the material Constant. 2-0 Time Variable. 2-d Distance ofconduction Do 2-e Temperature difi'erential Do "it was found that, in the operation as carried out previously to the present invention, the foltemperature of th above-mentioned parts were existent:

. gas flow curves are plotted against time in the dicated objectionable conditions and provides a method and apparatus which attain the following results:

1. To apply heat uniformly over the entire exposed area of the ingots.

2. To produce substantially complete combustion before the hot gases contact the surface of the ingot.

3. To control the velocity, direction and spread of the flame.

The adaptation of the present invention to a soaking-pit furnace for steel ingots is illustrated in the accompanying drawings, it being desired to emphasize, however, that the illustrated embodiment of the invention is intended to beonly by way of example, as it will be apparent, as has been pointed out above herein, that the invention is capable of being adapted to a wide variety 80 of conditions and uses.

The invention will be understood more readily by reference to the accompanying drawings, wherein,

Fig. 1 represents a plan view of a soaking-pit furnace which is bottom-fired by a burner constructed in accordance with the present invention, the view showing the furnace with its cover removed, and indicating the direction of heat application to steel ingots being treated in the furnace;

Fig. 2 is a sectional elevation through the furnace taken generally along the lines II-II of Fig. 1, but showing the cover of the furnace in position thereon;

Fig. 3 is an enlarged sectional elevation of a burner assembly which incorporates the prin ciples of the present invention;

Fig. 4 is a sectional plan view or an assembly of mounting vanes employed in the present invention the view being taken on the line IVIV of Fig. 3 looking in the direction of the arrows;

Fig. 5 is a diagrammatic view in sectional elevation of an ingot being heated in accordance with the present invention, the view showing by arrows and legends the heat flow and heat conditions within the ingot, the arrows indicating the direction of heat flow.

pit, the curves showing comparative results obtained by the previous type of burners and burninvention, the view showing the burner as installed in a soaking-pit furnace;

Fig. 10 is a sectional plan view taken on the line X-X of Fig. 9 looking in the direction of the arrows;

'Fig. 11 is a sectional plan view taken on the line XIXI of Fig. 9, looking in the direction of the arrows;

Fig. 12 is a further sectional plan view taken on the line XII-XIII of Fig. 9, looking in the direction of the arrows;

Fig. 13 is a further sectional plan view through the pipe column, taken on the line XIII HII of Fig. 9, looking in the direction of the arrows;

Fig. 14 is a sectional elevation taken along the line XIV-XIV of Fig. 10;

Fig. 15 is a sectional elevation taken along the line'XVXV of Fig. 10:

Fig. 16 is a plan view of a half-plate mounted at the bottom of the burner head, showing details of construction.

Referring more particularly to'the drawings, and first to'Figs. 1 through 5, reference letter A represents the laboratory of a, soaking-pit furnace, in which are placed ingots B, the furnace being heated by a burner assembly C mounted in the bottom D of the furnace by way of a port E provided for that purpose.

This air-port E is made from cast steel and is funnel-shaped; and it is set solidly in the brickwork of the furnace, which brickwork is extended upwardly and outwardly in line with the air-port E to form a crater H and downwardly to form an air passage [3 to which air passage an air feed pipe [5 is connected. The air-port E also provides reinforcement for the crater il'and brickwork against damage from falling ingots.

A modification of the air-port construction may consist of an extension of the cylindrical portion 4: through the furnace bottom to the air feed pipe time curv'esfthe curves indicating comparisons it, to which it could be connected by flanges or otherwise.

As illustrated in Fig. 2, an arrangement is shown in which the air passage 13 receives cold, or only slightly heated air from a supply conduit H, which opens into an air box is. Fig. 9 shows an arrangement of a burner using preheated air, where preferably the burner assembly is watercooled, although such cooling means would not be necessary if heat resisting metal is used for the burner assembly.

It will be seen from the drawings, a ga feed pipe ii is mounted in the air passage l3, the pipe 2! receiving gas from a pipe 28 by way of a T- connection 25, the pipe 2| being threaded as indicated at 21 adjacent its end which i inserted in the connection 25. The threads 21 operate in an internally threaded flange of the T-connection 25, by means of which threads the position of the feed pipe it may be adjusted and secured in adjusted position by a lock nut 3!.

The gas feed pipe 2| i maintained centered with remect to the air passage I3 by means of a guide flange I3 on the bottom of the air box I! and a spider 35 in the air-port E.

. It maybe noted in this connection, that when certain kinds or qualities of gas are used as fuel,

it may be necessary to interchange. or reverse the gas and air feeds of the burner.

With further reference to the drawing it will be noted that the gas feed pipe II is provided with a gas distributor 31, which sits on the top of the gas feed pipe II, and feeds the gas approximatelyhorizontally into the crater H where it mixes With'airto form a'mixing zone 98.

Although good results are secured with the parts related as shown on the drawings, it will be understood that it is not desired nor intended to limit the angles shown for either the distributor 3'! or the crater Ii. As has been mentioned above, there must be available maximum regulation and control of the flame in order to control all of the variables. The angles of the distributor and the crater are dependent on furnace sizes and shapes. Adjustment of the distributor 31, which sits solidly on top of the gas feed pipe 2 I, is accomplished by screwing the gas feed pipe in or out of the threaded flange 29.

With further reference to the construction 01' the distributor 31, it will be noted (Fig. 3) that the seating of the distributor on the feed pipe 21 is effected by means of a sleeve H which is adapted to slip snugly over the end of the feed pipe 25, thereby firmly holding the distributor on the feed pipe. A refractory shield 43 also is provided for protection of distributor 31. The distributor 37 is formed with a plurality of radially extending vanes #35, which distribute the gas evenly. Instead of being radial as shown, these vanes may be tangential to the gas feed pipe, or they may be spiral. A lifting ring 51 is provided for lifting this structure, and since the gas disit may be removed and replaced while the furnace is hot. The distributor may be of various shapes, sizes and proportion to meet varying conditions within the furnace. The same applies to the air-port E.

While the yanes as are shown extending to the periphery of the gas distributor, such is not an essential limitation as other types of vanes may be substituted, such as, for instance, stream-lined vanes extending only part way to the periphery of the distributors or a parabolic cone may be inserted into the gas feed pipe and supported therein by a spider or other suitable supporting means.

it will be observed that the top of the gas distributor 3'5 is located at an elevation well below that of the crater rim, which rim acts as a guard for the various parts of the burner against damage thereof from falling ingots.

Figs. 1 and 2 show diagrammatically the distribution of the dame within the furnace, which is secured by the present improved burner. It

will be seen from the drawings that the flame may be described as a thick bowl-shaped flame with a dared lip. The burner directs and shapes the flame so that it spreads directly on and is applied over the entire length of the ingots. The flame may be said to be literally sprayed on the ingots.

The hottest zone 59 is near the surface of the ingots whence it is in the best position for transfer of heat to the ingots. Additional control of the bowl-shaped flame is secured by furnace pressure control or manual operation of the stack damper.

The inside of the bowl of flame is a zone of recirculating gas 55 which is at a lower temperature than the direct flame, and which will not overheat or otherwise damage the brickwork oi the cover. Attention may be called here to the fact that at no place within the furnace is the flame played directly on the brickwork. a

Fig. 5 shows diagrammatically the heat con ditions interiorly of the ingot. The heated area or surface 53 is towards the flame and adjacent to the hottest zone 49, from which heat is received by the cold mass 55 which is towards the wall. Since heat travels the most direct path tributor a? has a sliding fit on the gas feed pipe,

from a hot to a cold portion, it will travel in the ingot as indicated by the arrows. With the uniform heat application as obtained by the present invention from top to the bottom of the ingot, which is of nearly uniform section, substantially complete soaking is obtained simultaneously throughout the entire length of the ingot.

In Fig. 5, it will be noted that there is a large area heated, which means greater capacity for heat absorption from the flame. With a large heated area, there is a large area for conduction. which means great capacity for heat conduction from the surface to the interior of the ingot. Short distances of conduction mean rapid heating, and the shorter are the distances of conduction, the less is the temperature difierential.

At this point, a general comparison may be made between the present invention and the results obtained in the prior art.

In the prior art, the burner customarily employed is a bottom fired type which mixes in a vertical chamber and directs the flame through a nozzle upwards againsttthe cover. the nozzle being formed entirely from refractory brick. Such burner produces a flame which may be described as mushroom in shape, the flame being the stem which extends up to the cover where it impinges on the brickwork, whence it is deflected outwardly to the walls where it is deflected again and curls downwardly to the tops of the ingots where it first contacts the ingots.

The result of this flame applicatmn is that the I ingot is hottest at the top, tapers oil down the sides and is coldest at the bottom. The zone of hottest flame is at the top of. the ingot, which is the area of greatest heat transfer. As the gas flows down the side, heat is transferred to that surface, but since the flames do not reach the bottom, there is no heat transfer there. There is only a small area of flame application which limits the rate of heat transfer, and a small heated area means a small area of conduction whlchlimits heat conduction away from the surface. Long distance (that is, end to end) of conduction increases the time of soaking. This ingot is soaked progressivelyfrom top to bottom which limits the rate of heating to the area of conduction and increases the time with the distance of conduction. Also, the greater the distance of conduction, the greater the temperature diil'erential.

In order to alleviate such inefficiencies, it has been proposedin the prior art to tand the ingots upright in the soaking-pit, so that the gas can flow behind the ingots. However; in such practice there is very grave risk involved because of the danger of falling ingots and the hazards of damage resulting therefrom, which is inevitable when the ingots are stood on end.

Consequently, the practice which is followed customarily, is to lean the ingots against the wall of the soaking-pit. and then, in accordance with prior burner construction, practically no flame From this point it flows down the sides of the ingots and escapes through v Among the advantages of the present construction there may be mentioned the following, although these specifically mentioned advantages do not by any means delimit the improvements which are resident in the present construction:

1. By sperading the flame over larger areas, more heat transfer is possible; with a larger heated area, a, larger section for heat conduction is assured.

2. By heating the side of the ingot, the distance of heat conduction is shorter; with shorter distance. of heat conduction the temperature differential is less. With more Heat transfer and shorter distance of conduction, the burner of the present invention heats the ingots faster and more uniformly than has been possible heretofore; obviously, reduced heating time means increased capacity. Also, with a smaller difierential of temperature the ingot is in better condition for rolling which is reflected in the quality of the finished steel products. A larger area of heating reduces the danger of overheating the steel, on account of the larger area being better able to absorb variations in flame application, and for the same reason, a greater range of forced operation is possible.

3. Maximum ingot temperature can be kept at least 100 F. lower than heretofore, for the same type of steel in each pit. which gives an additional margin of safety against overheating, thereby reducing the danger of damage to the ingot by burning and washing.

4. Since the flame is not directed against the top of the ingot, the piping in the ingot is not aggravated.

5. There are longer life of refractoriesin the furnace, and greater fuel economy, with increased production of first quality rolled products resulting from the ingots.

6. Greatly decreased power consumption is effected during rolling, due to the ingots being completely soaked.

7. If an ingot falls across the improved port and burner, damage is avoided, since the burner is below the plane of the rim of the port crater, whereas in the previous burner of the prior art, a falling ingot destroys the part and necessitates shutting ofi of the pit for at least forty-eight hours for repairs.

8. With the present improved burner, it is virtually impossible for the pit to become unbalanced and result in overheated ingots on one side and cold ingots on the opposite side. I

9. The present improved burner is very flexible in operation in that any type of flame may be obtained from luminous to non-luminous by simple adjustments of the burner.

' taken from actual soaking-pit operations.

peratures weretaken by thermocouples inserted Reference now may be had 'again to the drawings and particularly to Figs. 6, '7 and 8.

Fig. 6 shows typical temperature-time curves Tem- ' tinuous temperatures on their charts.

Curves A and -B of Fig. 6 are records of an ingot curves are shown in a single view for purposes of comparison.

Referring first to the A-B pair of curves, it will be noted that the temperature of the top of the ingot (curve A) rises very rapidly while the bottom lags far below. At the point ar, the control temperature is reached, and the controls reduce the gas supply to maintain constant temperature. This reduced gas supply is reflected immediately in a flattening of curve B. The point :11 indicates the beginning of the soaking period which continues to the "ready to roll" point as. This point a: is an empirical point determined by economic considerations. It is that point at which the temperature difierential will permit rolling of the ingot without much damage to the steel or requiring too much power. Reduction of temperature differential would improve rolling conditions and finished products but would increase soaking-pit time excessively. Curve A shows 3% hours elapsed time between points or and an, which is the soaking time. During this time curve B shows an increase of about 65 F. from hi to b: which is at the rate of about 20 F. per hour. At the point az the temperature differential between curve A and curve B is 300 F. If it were desired to reduce that to 200 F., it would require 100 F. increase in the temperature of curve B, which at 20 F. per hour would require 5 additional hours. Adding this to the present pit time of six hours would make a total of eleven hours.

By comparison, curves C and D now may be examined. It will be found from this pair of curves that the temperature of the ingot bottom (curve D) takes the lead and maintains it to-the point or, where curve C crosses curve D, and takes a small lead. Curve C reaches the control point c: where the gas flow is regulated to maintain constant temperature. Curve D then reacts to the reduced gas flow and flattens out. The "ready to roll" point is indicated at 03. This is an empirical point which has been selected to satisfy any doubt as to complete saturation. Curve D indicates saturation almost immediately after the point c: is passed. This point is verified on Fig. 7. Y

The curves in all cases were taken under identical conditions and are compared on that basis.

The results obtained by the use of the improved flame control burner of the present case and by the comparison burner of the prior art may be compared further as shown in the following table (Table I), and which refers also to the curves of Fig. 6.

Table I Burner Prior burner Improved burner Soaking pit N0 4E. Temperature control poln Max. gas flow, period "co" to 2."

Max. gas flow, time Max. gas flow, max. temp.

difl. Ready to roll point Soaking, period Soaking, time.

2 hr. 45 min... 540 F 3 hr. 35 min. 60 F.

11 to 1 hr. 30 min. 5 hr. 6 min. 55 min.

- Temp. difl. t control point". cf-60 F. Temp. diif. at "ready to roll". cf-60 F. Mean tom at "ready to ro "c;2330 F.

heated in the manner, and in accordance with the teachings, of the prior art, whereas curves C and D are the records of an ingot heated by the improved bumer of the present invention. These (approx.

Examination of this table shows the improved gradient which indicates that temperature drop is proportional to the distance of conduction. Since the prior art type 01 burner heats the top whereas the curves on Fig. 'I are for single charges. Reference is made, however, to Fig.

8 at transit time of 3 hours, 35 minutes (which is the same as for Fig, 7) where the curve for the original burner'oi' standard type shows a rate of 16.5 tons per hour and the improved flame control burner" of the present invention shows a rate of 26.5 tons per hour, giving an advantage (So for the improved burner.

Figs. 1 through 5 illustrate the burner of the present invention as being adapted for use primarily-with cold air, although air preheated to a suitable extent also may be utilized. There is shown in Fig. 9 a construction which is adapted to use, primarily, air which has been preheated to a temperature sufiiciently high to render desirable the inclusion of cooling means in the of the ingot, conduction is from end to end,

lengthways; whereas the improved flame control burner oi the present invention heats the side of the ingot, conduction is from side to side, crossways. Therefore, according to the temperature gradient, the temperature diflerentials should to each other as the thickness of the ingot is to its length. The curves of Fig. 6 show that approximately these conditions do prevail at the ready to roll" points. On these curves, the relation or ratio is shown in which, the difference c; to do, is is a: to b2, as the thickness of the ingot, is to the length of the ingot.

A further consideration is that, around rolling temperatures, for-every drop of 100 F. in temperature (for steel containing 0.30% carbon, for instance) the strength increases 1,000 pounds per square inch so that an ingot having a temperature differential of 300 F. would increase its resistance to plastic deformation 3,000 pounds per square inch from end to end in passing through' the rolls. Since this approximately 100% increase in strength, it would explain some broken rolls, and this constitutes a further reason for a smaller temperature differential.

Figs. 7 and8 may be referred to briefly.

Fig. 7 shows temperature and gas flow curves for both types of burners, plotted against time in the pit. A comparison of results secured is given in the following table (Table II).

Table II Burner Prior burner Improvedburner iiii gis ii feissijiiiiii: 2 i ialomm.

Max. gas flow, rate Control tam M00 Ready to re gas flow rota...

Tons per hour Advantage, pit time Advantage, pit time, percenL.

Advantage, tons per hour Total gas consumption (appros.

average curves covering a period of six days.

burner structure in order to avoid destructive overheating of the burner.

In Fig. 9 the crater ll, of the construction of Figs. 1 through 5, is replaced by refractory brickwork 51 which receives the air-port 58, which conveniently is a steel casting provided with an anchoring flange 5| extending into the brickwork 51. Preheated air is admitted to the air-part5! through a conduit 63 which passes beneath the courses of the bottom brickwork 55 and thence upwardly to the air-port 59. The airport 58 is cooled by water circulating through pipe 81 mounted in brickwork 51.

The burner head, which will be referred to in greater detail hereinafter, comprises an upper chamber 65 and a lower chamber H, the chambers 59 and II being interconnected through tubular separators 13, 15 which in turn are separated by a baifle artition "in upper chamber 68. The lower chamber 1 i which is cone-shaped, is divided by a transversely extending partition 19 into ascending and descending sections, the ascending section being sealed at the bottom by a half-plate M which is apertured suitably as iaridicated at 82 to receive a water supply pipe As shown, the tubular separators 13, of which there are two in number, are water-supply separators, the separators 15, also two in number being outlet separators, so that cooling water will flow upwardly through the conical lower section H and through riser separators l3, 13 around the ends of the baflie partition ii and down through outlet separators 15 thence out from the conical lower section, as will be described hereinafter in greater detail.

From the drawings, it will be seen that the conical section 1! of the burner head is the top flaring end of a sleeve 85, in which sleeve is 10- cated a fuel supply pipe 81, which defines a space 84 between it and the sleeve 85, in which space is located the water supply pipe 83.

The fuel supply pipe 81 is threaded at its bot tom end as is indicated at 89, the threaded end being introduced into a threaded flange 8i mounted on a supporting column 93 into which In operation, gas passes from the supply means 95 into the centrally located gas pipe 81, to the burner head, where it is deflected by the bottom of the top compartment 69 and distributed hereby in a horizontal circular plane through an annular gas port I05, where it mixes with preheated air in the air-port casting 59, and burns.

Water passes up through pipe 83 into the conical bumercompartment ll, where it is caused to flow, by virtue of the partition 19 and half- 10 plate 8| which forms a bottom for the intake side of the burner compartment, upwardly into compartment 69, through the riser separators 13, 13, around baffle 11 in compartment 89, and thence down through stream-lined separators 15 to the 15 outlet side of the lower burner compartment 1|, the upper compartment 69 therefore serving as a water cap for cooling the burner. The water thence flows down through space 84 and out by discharge connection I01.

The burner itself is protected by a refractory cap I09 which is placed on the top of the burner assembly.

The fuel supply pipe 81 engages the half-plate 8| in alnotch 8|- of the latter, which notch is of a size and shape suitable to engage the pipe 8'! and to flt therearound. The plate BI is welded in position, the plate 8|, together with partitions 19 causing the water to flow upwardly through compartment II and into the top compartment 69, the course of the water circulation being indicated by the arrows.

The refractory cap I09 effectively provides insulation against the radiant heat from above, and it will be observed that the annular gas port I05 directs the gas horizontally into the air-port 59, thereby effecting an intimate combustion mixture, the flame from which is directed by the crater form casting of the air-port in the manner described above in connection with Figs. 1 to 4 inclusive, effecting the lateral heating of the ingots as described above herein.

We claim:

l. A burner for heating objects distributed laterally thereabout in a furnace and supported by the furnace structure, which comprises in combination, crater-like flame-deflecting and guiding means for the bottom of the furnace, a fuel supply column, a burner head mounted on the column and supported thereby, the burner head being positioned in the said crater-like means, air supply means for supplying air to the craterlike means for mixing air with fuel issuing from the burner head; the resulting intimate mixture\ being burned at the crater means, and mechanism for adjusting the height of the said fuel supply column and burner head, the said craterlike means being adapted to deflect the flame of the said burning mixture substantially laterally of the furnace whereby objects being heated in the furnace receive substantially laterally at least the major portion of the said flame.

2. A burner for heating elongated'objects disposed laterally thereabout in a furnace and supported by the furnace structure with the major axis -of the objects substantially vertical, which comprises; in combination, crater-like flame-deflecting and guiding means for the bottom of the furnace, a fuel supply column,a burner head .mounted on the column and supported thereby,

the burner head being positioned in the said crater-like means, air supply means for supplying air to the crater-like means for mixing air with fuel issuing from the burner head, the resulting intimate mixture being burned at and in the crater-like means, the said crater-like means being adapted to deflect the flame of the said buming mixture substantially laterally of the furnace, whereby objects being heated in the furnace receive laterally at least the major portion of the said flame for assuring minimum paths of heat conduction through the objects being heated, thereby producing accelerated and uniform heating of the objects throughout their entire extent, and protecting means for the burner head to protect the same from damage incident to any of the said objects being heated falling against. the burner head.

3. A burner for heating objects distributed laterally thereabout in a furnace and supported by the furnace structure, which comprises in combination, crater-like flame-deflecting and guiding means for the bottom of the furnace, the said means including a crater-form castin mounted in the bottom of. the furnace, a burner head projecting into the casting, a fuel supply column for the burner head, fuel ports in the burner head adapted to direct fuel from the head substantially horizontally in the crater casting and air supply means for supplying air under pressure into the said crater casting and for effecting an intimate combustion mixture with the said fuel, the said crater-like casting being adapted to deflect the flame of the said burning mixture substantially laterally of the furnace, whereby objects being heated in the furnace receive laterally at least the major portion of the flame.

4. A burner for heating elongated objects disposed laterally thereabout in a furnace and supported by the furnace structure with the major axis of the objects substantially vertical which comprises in combination, a, flame-directing crater-like casting mounted in the bottom of the furnace, a burner head projecting into the said casting substantially axially thereof, a fuel supply column for the burner, fuel outlet means in the burner head adapted to direct fuel from the tially laterally in the furnace, thereby heating substantially laterally the objects being heated placed substantially uprightly in the furnace, while defining interiorly of the cone-like zone a region of recirculating hot flame and combustion products thereof, and means for adjusting the fuel supply column relative to the said casting and air supply means.

5. A metallurgical furnace comprising the combination with a furnace chamber adapted to receive metal ingots to be heated therein, of a burner assembly mounted in the bottom of the chamber, the assembly comprising a vertically positioned burner head provided with lateral fuel egress means, flame-deflecting instrumentalities positioned adjacent to theburner head, air intake means intermediate the burner head and flamedeflecting instrumentalities for mixing air with fuel emerging from the burner head to form an.

intimate combustion mixture with the fuel, and fuel supply means for the burner head, the said flame-deflecting means being positioned relative to the burner head and chamber and angularly disposed relative thereto to deflect laterally,

flow through the ingots for facilitating uniform,

heating of the ingots throughout their entire extent.

6. A metallurgical furnace comprising the combination with a furnace chamber adapted to receive metal ingots to be heated therein, of a burner assembly mounted in the bottom of the chamber, the assembly comprising a burner head projecting substantially vertically into the furnace for a substantial distance, fuel supply means for the burner head, the said burner head being provided with a lateral fuel port adapted to discharge fuel laterally into the furnace, means adjacent to the burner head for deflecting at least the major portion of flames from the fuel, when burning, onto the ingots being heated laterally of the ingots, so that the said ingots have side areas entirely swept by the said flames for uniform heating thereby, and means for protect the burner head from mechanical damage resulting from an ingot falling thereagainst.

'7. A metallurgical furnace comprising the combination with a furnace chamber adapted to receive metal ingots to be heated therein, of a burner assembly mounted in the bottom of the chamber, the assembly comprising a burner head projecting vertically into the furnace for a substantial distance, fuel supply means for the burner head, the said burner head being provided with a lateral fuel port adapted to discharge fuel laterally into the furnace,a refractory crater-like deflector positioned in the furnace chamber adjacent to the burner head for deflecting at least the major portion of flames from the fuel when burning, onto the ingots being heated, in a direction laterally of the ingots, so that the said ingots have side areas entirely swept by the said flames for uniform heating thereby, and a refractory cover overlying the burner head for protecting the said head from radiant heat of the furnace and the hot steel above.

8. A metallurgical furnace I comprising the combination with a furnace chamber adapted to receive metal ingots to be'heated therein, of a burner assembly mounted in the bottom of the chamber, the assembly comprising a burner head projecting vertically into the furnace, fuel supply means for the burner head, the said burner head being provided with a lateral fuel port adapted to discharge fuel laterally into the furnace, a refractory crater-like flame-deflector pochamber adjacent to the burner head for deflecting at least the major portion of flames from the fuel, when burning onto the ingots being heated in a direction laterally of the ingots, so that the said ingots have side areas entirely swept by the said flames for uniform heating thereby, a refractory cover for protecting the said head from the radiant heat above, and crater-likecasting for protection from mechanical damage resulting from an ingot falling thereagainst, and means for circulating a cooling fluid through the said burner head, and a cover for protection from the radiant heat.

10. A metallurgical furnace comprising the combination with a furnace chamber adapted to receive metal ingots to be heated therein, of a burner assembly mounted in the bottom of the chamber, the assembly comprising a burner head projecting vertically into the furnace for a substantial distance, fuel supply means for the burner head, air supply conduit means exterior of the burner head, the said burner head being provided with a lateral fuel port adapted to discharge fuel laterally into the furnace to be mixed the said head from radiant heat above, and

. crater-like casting for protection from mechanisitioned in the furnace chamber adjacent to the burner head for deflecting at least the major portion of flames from the fuel when burning onto the ingots being heated in a direction laterally of the ingots, so that the said ingots have side areas entirely swept by the said flames for uniform heating thereby, and means for circulating a cooling fluid through the said burner head for avoiding overheating thereof.

9. A metallurgical furnace comprising the combination with a furnace chamber adapted to receive metal ingots to .be heated therein, of a binner assembly mounted in the bottom of the chamber, the assembly comprising a burner head projecting vertically into the furnace for a substantial distance, fuel supply means for the burner head, the said burner head being provided with a lateral fuel port adapted to discharge fuel laterally into the furnace, a refractory craterlike deflector casting positioned in the furnace cal damage resulting from an ingot falling themagainst, and mechanism for adjusting the position of the burner head with its fuel supply means relative to the said crater-like casting and air supply conduit for obtaining a flame Of predetermined properties in the furnace chambers.

11. A metallurgical furnace comprising the combination with a furnace chamber adapted to receive metal ingots to be heated therein, of a burner assembly mounted in the bottom of the chamber, the assembly comprising a burner head projecting vertically into the furnace for a substantial distance, fuel supply means for the burner head including a, fuel supply conduit, an air supply conduit enclosing the fuel supply conduit for supplying air to fuel from the burner head exteriorly of the burner head, the said burner head being provided with a lateral-fuel port adapted to inject fuel laterally into the furnace and into air supplied by the air supply conduit exteriorly of the burner head, a fuel supply line for supplying fuel to the said fuel supply conduit, a refractory crater-like deflector positioned in the furnace chamber adjacent to the burner head for deflecting at least the major portion of the flame from the resulting fuel-air mixture onto the ingots being heated, in a direction laterally 0f the ingots, connecting instrumentaiities between the fuel supply line and the fuel supply conduit, and adjusting means in the said-connecting instrumentalities for adjusting the position of the fuel head relatively to the air supply conduit and to the crater-like deflector for obtaining a flame of predetermined properties in the furnace chamber.

12. A metallurgical furnace comprising the combination with a furnace chamber adapted to receive metal ingots to-be heated therein, of a burner assembly mounted in the bottom of the chamber, the assembly comprising a burner head projecting vertically into the furnace for a substantial distance, fuel supply means for the burner head including a fuel supply conduit, an air supply conduit enclosing the fuel supp y conduit for supplyinfl air to fuel from the burner head exterior of the burner head, the said burner head being provided with a lateral fuel port adapted to injectfuel laterally into the furnace and into air supplied by the air supp y conduit exteriorly of the burner head, a fuel supply line for supplying fuel to the said fuel supply conduit, a refractory crater-like deflector positioned in the furnace chamber adjacent to the burner head for deflecting at least the major portion or the flame from the resulting fuel-air mixture onto the ingots or the like being heated in a direction laterally of the ingots, connecting instrumentalities between the fuel supply conduit and the fuel supply line, and adjusting means in the said connecting instrumentalities comprising a threaded end for the fuel supply conduit, a threaded flange for receiving the said threaded end whereby upon a turning of the fuel conduit or the flange, the burner head is adjusted correspondingly to the air supply conduit for controlling mixing of air and, fuel to impart corresponding predetermined properties to the said flame.

1a. a metallurgical furnace comprising the projecting vertically into the furnace for a substantial distance, a fuel supply conduit for the burner head, a sleeve enclosing the fuel conduit and spacedtherefrom to form an annular space around the said fuel conduit, means dividing the burner head into a closed lower compartment and a closed upper compartment, an annular laterally extending fuel port into which the fuel supply conduit opens; an air supply conduit enclosing the fuel supply conduit and sleeve. the said fuel port being adapted to inject fuel exteriorly and laterally of the'fuel head into a supply of air issuing from the air conduit, a refractory craterlike flame-deflector casting positioned in the furnace chamber adjacent to the burner head for deflecting at least the major portion of the flame from the resulting fuel-and-air mixture onto ingots or the like being heated, in a direction laterally of the ingots, connecting ducts intercommunicating with the bottom and top compartments of the burner head, partition means in the compartments intermediate the said ducts for dividing the saidcompartments into fluid intake and fluid outlet sections, a supply pipe for cooling fluid positioned in the annular space between the fuel supply 'bonduit and the sleeve therearound, the fluid supply pipe opening into the fluid intake section of the bottom compartment, thence passing into the fluid intake section of the upper compartment, thence into the fluid outlet section of the upper compartment, thence down into the fluid outlet section of the lower comparment, whence-the fluid exits throuah the said annular space between the sleeve and fuel I 'supply conduit.

mm: A. connm'. HARRY r. 

